This invention relates to an apparatus for measuring oxygen consumption and the exchange of other breathing gases.
In the field of medical diagnostics, the importance of oxygen consumption in a human being, as a parameter of both the body energetic requirements and circulatory events, such as heart flow rate, is well known.
The measuring methods currently employed for this purpose are based upon the measurement of the difference between the amount of oxygen acquired through inhalation and the amount of oxygen exhaled. Therefore, such methods involve a measurement of the volume of gas inhaled in the unit time and the analysis of the oxygen concentration in the inhaled gas, usually envinronmental air, and exhaled gas by the patient. For taking these two different measurements, various instruments are known, which are not devoid of shortcomings, such as lack of accuracy, a very delicate maintenance procedure, and high cost. Also disadvantageous is the complex procedure involved in taking such measurements and the need of carrying out successive calculations, so that those measurements have been limited heretofore to experimental purposes.